Sensor tapes allow gathering of data from surfaces that is generally more accurate than other types of sensors because the sensors conform to the surface. This allows a more accurate reading along the surface, whether planar or curved, and therefore provides more accurate data to analysis and read out electronics. Moreover, sensor tapes may be manufactured by inexpensive fabrication processes that pose limitations on the sensor design. However, since the fabrication is inexpensive, tapes with multiple sensors and distributed sensors can be made. Therefore, multiple sensors on one tape in different locations compensate for the lack of performance of the individual sensors.
Current sensor tapes include VarioSens data loggers from KSW-Microtec. Generally, these consist of adhesive ‘labels’ that monitor temperature and may include a radio frequency identification (RFID) tag. The loggers are started at the beginning of a sensing episode and then the information logged is downloaded to a PC or RFID card reader at the end.
Other examples include medical skin patches, such as a biopolymer skin patch available from ISIS, Alza's E-Trans, and the iontophoretic patch available from Vyteris. These are generally square or round patches that have individual sensor electrodes, but are not monolithically integrated. This is similar to the VarioSens data loggers, as each one is a discrete component.
A disadvantage of these discrete components is that they are not very useful when attached to an object having multiple points upon which readings are actions are desired. Each individual sensor component may be mounted in different areas of the curved surface, but they would have to be somehow tied together to model the surface. This leads to a less-than-robust sensing solution and has an increased complexity.